maths urgesnt help

[regmimanish]

A (7,2) and c (1,4) are two vertices of a square ABCD
a) Find the equation of the diagonal BD
b) Find the coordinates of B and of D
PLz help me with part b question
thnx

 

[1357913579]

is this questionfrom p1 or p3

 

[elbeyon]

I'm not quite sure but I think this will help

 

[regmimanish]

thnx but i guess .. its too lengthy anywaz thx

 

[elbeyon]

Yup its too lengthy and time consuming but it is the only method I knew so I shared it. Anyway its better to solve it by any way possible then loosing marks in exam.

 

[unique840]

i m not sure about the method whether it is correct or not cox its been 2, 3 months since i've touched p1. well what i did was to calculate the gradient of AC (already calculated in the first part). then i used the formula,
m = tan theta
the theta shud be 45 if the line AB wud be horizontal. so after finding theta i subtracted 45 from it to find the theta between horizontal and AB. after getting theta i used the same formula stated above to find the gradient of AB. AC is perpendicular to AB so gradient can b found. thn find the equations of AB and BC and solve simaultaneously to find the cordinates of B. gradients of CD and AD will be same as of AB and BC respectively. same will be dun. 2 equations solved simultaneously.
gradient of AB can b found by a shorter method but i dun remember any other method. hope it helped u though

 

[elbeyon]

If you didn't get correct ans. by either method then I think the question you mentioned is not complete. Look at the question again. In question either point B or D must lie on x-axis or y-axis. If it is so then it will be lot easier to solve it.

 

[1357913579]

CAN YOU TELL ME THE ANSWER BECAUSE I HAVE ALMOST SOLVED IT BUT NEED CONFIRMATION IT TOOK ME AROUND LOTS OF PAGES NEVER MIND JUST TELL ME THE ANSWER QUIKLY PLEASE.

 

[regmimanish]

a ) 3x-y=9
b) (3,0) AND ( 5 , 6 )